Legionella are bacteria that live naturally in water and soil. Like most bacteria, there are harmless species that live in the environment and those that are harmful to us. Legionella pneumophila is the harmful bacteria that causes Legionnaires disease. Legionella are that live in natural water sources such as lakes and rivers, as well as artificial or man-made water systems. It is when the bacteria get into these water systems that they are able to cause Legionnaires disease.

Legionnaires disease is a form of pneumonia caused by Legionella bacteria, which kills about 13% of those infected. The disease is caught by breathing in aerosols (which are formed from fine water droplets) containing the Legionella bacteria.

When water droplets are formed (showers, jacuzzis, flushing a toilet, cooling towers, fountains, etc.), there is the risk of Legionella infection. Below are businesses at risk as a result of these droplet formations:

• Hotels and restaurants
• Residential complexes
• Commercial buildings
• Industrial companies (cooling towers and air-conditioning)
• Shipping
• Schools
• Sports halls, swimming and leisure pools, spas and saunas
• Dental practices
• Hospitals and care homes

Our consultants and accredited laboratory technicians offer a range of services to help your business avoid Legionella contamination. These include:

• Sample collection and laboratory analysis of a variety of water sources.
• Legionella risk assessments
• Risk management planning

Our scope of accreditation has also been extended to include detection and enumeration of Legionella spp in water: (potable, bottled, irrigation, borehole, estuary, tower, marine, waste, industrial, effluent, sewage, and ground.)

Our professional testing and water quality analysis solutions for the detection of Legionella and other waterborne bacteria include:

• Legionella testing analysis. Expert SANAS accredited laboratory tests for Legionella bacteria ISO 11731 (SANS 11731) and technical support services.
• Additional water tests. Comprehensive suite of additional laboratory-based water, microbial and outsourced chemical tests such as SANS 241.
• In-field sampling. We provide expert in-field water sampling and advice.

In many cases, the benefits of carrying out routine legionella testing far outweigh the potential health and legal risks involved from not carrying out Legionella testing. Regular testing for legionella can help prevent potential and sometimes fatal outbreaks of Legionnaires’ disease.

Furthermore, routine Legionella testing helps to safeguard the health and well-being of guests, building occupants, tenants, and visitors to any facility. With our SANAS accredited laboratory test results, we provide the results to support and help protect building owners and managers against potential litigation in the event of an outbreak.

The regular monitoring for Legionella bacteria in addition to the Legionella risk assessments will help create or supplement a comprehensive maintenance program and will serve to demonstrate a clear action of due diligence whilst ensuring the program is working effectively.

The testing of Legionella in water is a complex and specialized test

The Legionella testing service is a complex and specialized series of tests that are performed by specially training laboratory technicians. Our accredited method requires rigorous tests designed to isolate any potential presence of Legionella bacteria, and then to further determine the presence of the pathogen Legionella pneumophilia. Unlike our standard water tests, which take 2 – 3 days to complete. The testing of Legionella bacteria takes 7 – 10 days.

The international standard used to test for the detection and enumeration of Legionella species is ISO 11731 (SANS 11731). This method is useful for a variety of environmental samples including potable, industrial, and natural waters as well as associated materials such as deposits, sediments, and slime.

Sampling is conducted by trained technical consultants, in sterile polyethylene sampling bags. Samples are transported under 10°C, protected from heat and sunlight in cooler boxes.

The bacteria in the water sample can be concentrated by centrifugation. The sample is shaken to resuspend any deposit that may have settled. It is then dispensed into sterile screw-capped conical bottom bottles and centrifuged for 30 minutes at 3000 g. The supernatant is removed aseptically and discarded. The deposit is then resuspended in a specified volume of diluent, this concentrate is now referred to as the prepared sample.

The prepared sample is then divided into three portions, one is used without any further treatment and the other two portions are subjected to acid treatment and heat treatment.

The prepared sample is pipetted onto specialized agar plates and incubated for up to ten days. The plates are observed at least three times at intervals of 2 to 4 days during the ten-day incubation period. A ten-day incubation period is recommended as Legionella are slow-growing and may be masked by the growth of other bacteria.

Colonies are further confirmed according to serogroup-1, serogroup 2-14, or Legionella spp., using a latex test kit.